Tokaido had checkpoints at various intervals to ensure that travellers were bonefide and to protect the Shogun in the capital, Edo. Hakone was the closest checkpoint to Edo, so was one of the most severely policed. Perched between the waters of Lake Ashinoko and the steep mountainous terrain of Hakone, Tokaido travellers had no alternative but to submit to inspection.
Kodama Tokaido Shinkansen slides smoothly into Kakegawa station. Out the window, the white walls of the castle atop a hill-top grab attention. Kakegawa Castle is important in Japanese history, being part of the story of the growing power-base of Tokugawa Ieyasu, Japan's most famous Shogun who started the Edo Period and set up a new capital in what is now modern-day Tokyo. Also in the castle you can see the 3 leaf ensign of Yamauchi, the local lord assigned to Kakegawa Castle by Tokugawa. The ensign looks vaguely familiar for a reason - it is the base for Mitsubishi's three-diamond brand.